The Tide Is Turning for a New Source of Green Energy

The "world's first large-scale underwater energy farm" is being built off the coast of Scotland, and is expected to start producing power in 2017.

When completed, the MeyGen project will produce enough power to light up 175,000 Scottish homes, and may ultimately include the construction of as many as 269 undersea turbines – the first four of which are scheduled to be completed by the end of the year.

Two turbines installed off Scotland’s coast aren’t harnessing the country’s winds to generate power. Instead, these blades are spinning underwater, using an even more predictable renewable power source in the region—tides.

The offshore array is the world’s first network of tidal turbines to deliver electricity to the power grid, according to Nova Innovation, the company behind the development.

That’s a big step for green power generation, as it shows commercial viability for a marine-based power source to create renewable energy. Unlike solar and wind power, where power production stops when the sun isn’t shining or when the wind stops blowing, Nova’s tidal arrays continuously generate electricity by using perpetual incoming and outgoing tidal currents to spin its underwater turbines 24 hours a day, 365 days a year.

“We are absolutely delighted to be the first company in the world to deploy a fully operational tidal array,” said Simon Forrest, managing director of Nova Innovations. “Deploying the second turbine truly sets us apart and showcases our technology.”

So far, two 100-kilowatt turbines have been installed in the turbulent tidal stream of Bluemull Sound off the Shetland Islands—an archipelago about 120 miles north of mainland United Kingdom, where the North Sea meets the Atlantic Ocean. Nova is planning to construct five turbines in the region, providing power to residents and businesses on the Shetland Islands.

The islands aren’t connected to the U.K. grid, so its 23,000 residents rely on a diesel-fueled power station for most of their electricity. The 0.5 megawatts expected to come online from the underwater turbines would minimize the need for the tanker-supplied fossil fuels.

Lang Banks, director at World Wildlife Fund Scotland, said the tidal array is an example of how the technology can help communities reach emissions reduction goals.

“Alongside energy-saving measures, marine renewables—including tidal—will have a critical role to play in helping Scotland reduce climate emissions as we phase out polluting fossil fuels and nuclear power,” Banks said. “Globally, tidal power has huge potential, which is why countries such as Japan are researching this type of energy technology.”

While the $3.9 million Shetland tidal project is small, marine energy’s potential looms large. Renewable energy agency U.K. Carbon Trust estimates a $165 billion global tidal energy market could be developed by 2050. The thousands of potential locations for tidal turbines could boost zero-emission energy, eliminating millions of pounds of greenhouse gas emissions that would otherwise be released through fossil-fuel-burning power plants.